// 进行sha的加密
let shl = {
  'hexcase': 0,
  hex_sha1(s) {
        let binarray = this.core_sha1(this.AlignSHA1(s));
        var hex_tab = this.hexcase ? "0123456789ABCDEF" : "0123456789abcdef";

        var str = "";

        for (var i = 0; i < binarray.length * 4; i++) {

            str += hex_tab.charAt((binarray[i >> 2] >> ((3 - i % 4) * 8 + 4)) & 0xF) +

                hex_tab.charAt((binarray[i >> 2] >> ((3 - i % 4) * 8)) & 0xF);

        }

        return str;

    },
    core_sha1 (blockArray) {
      var x = blockArray; // append padding
       var w = Array(80);

       var a = 1732584193;

       var b = -271733879;

       var c = -1732584194;

       var d = 271733878;

       var e = -1009589776;

       for (var i = 0; i < x.length; i += 16) // 每次处理512位 16*32
       {

           var olda = a;

           var oldb = b;

           var oldc = c;

           var oldd = d;

           var olde = e;

           for (var j = 0; j < 80; j++) // 对每个512位进行80步操作
           {

               if (j < 16)
                   w[j] = x[i + j];

               else
                   w[j] = this.rol(w[j - 3] ^ w[j - 8] ^ w[j - 14] ^ w[j - 16], 1);

               var t = this.safe_add(this.safe_add(this.rol(a, 5), this.sha1_ft(j, b, c, d)), this.safe_add(this.safe_add(e, w[j]), this.sha1_kt(j)));

               e = d;

               d = c;

               c = this.rol(b, 30);

               b = a;

               a = t;

           }

           a = this.safe_add(a, olda);

           b = this.safe_add(b, oldb);

           c = this.safe_add(c, oldc);

           d = this.safe_add(d, oldd);

           e = this.safe_add(e, olde);

       }

       return new Array(a, b, c, d, e);
    },
    AlignSHA1 (str) {
      var nblk = ((str.length + 8) >> 6) + 1,
            blks = new Array(nblk * 16);

        for (var i = 0; i < nblk * 16; i++)
            blks[i] = 0;

        for (i = 0; i < str.length; i++)

            blks[i >> 2] |= str.charCodeAt(i) << (24 - (i & 3) * 8);

        blks[i >> 2] |= 0x80 << (24 - (i & 3) * 8);

        blks[nblk * 16 - 1] = str.length * 8;

        return blks;
    },
    safe_add (x, y) {
      var lsw = (x & 0xFFFF) + (y & 0xFFFF);

       var msw = (x >> 16) + (y >> 16) + (lsw >> 16);

       return (msw << 16) | (lsw & 0xFFFF);
    },
    rol (num, cnt) {
      return (num << cnt) | (num >>> (32 - cnt));
    },
    sha1_ft (t, b, c, d) {

        if (t < 20)
            return (b & c) | ((~b) & d);

        if (t < 40)
            return b ^ c ^ d;

        if (t < 60)
            return (b & c) | (b & d) | (c & d);

        return b ^ c ^ d; // t<80
    },
    sha1_kt (t) {
      return (t < 20) ? 1518500249 : (t < 40) ? 1859775393 : (t < 60) ? -1894007588 : -899497514;
    }
}

module.exports = shl;
